(2S,3R)-3-[N-(mercaptoacetyl)]amino-2-hydroxy-4-phenylbutanoic acid 、 (2S,3S)-3-[N-(acetylthioacetyl)]amino-2-hydroxy-4-phenylbutanoic acid 、
(2S,3S)-3-[N-(mercaptoacetyl)]amino-2-hydroxy-4-phenylbutanoic acid 、 (2S,3R)-3-(N-L-cysteinyl)amino-2-hydroxy-4-phenylbutanoic acid 、 N-{(2S,3R)-3-[N-(acetylthioacetyl)]amino-2-hydroxy-4-phenylbutanoyl}glycine 、 N-{(2S,3R)-3-[N-(acetylthioacetyl)]amino-2-hydroxy-4-phenylbutanoyl}-L-leucine 、 (2S,3R)-3-[N-(2-benzoylthiopropionyl)]amino-2-hydroxy-4-phenylbutanoic acid 、 (2S,3R)-3-[N-(3-benzoylthiopropionyl)]amino-2-hydroxy-4-phenylbutanoic acid 生成 (2S,3R)-3-[N-(acetylthioacetyl)]amino-2-hydroxy-4-phenylbutanoic acid